eee6cad2cf
The change relies on a refactor of the upstream resumable sha256/sha512 package that opts to register implementations with the standard library. This allows the resumable support to be detected where it matters, avoiding unnecessary and complex code. It also ensures that consumers of the digest package don't need to depend on the forked sha implementations. We also get an optimization with this change. If the size of data written to a digester is the same as the file size, we check to see if the digest has been verified. This works if the blob is written and committed in a single request. Signed-off-by: Stephen J Day <stephen.day@docker.com>
41 lines
1004 B
Go
41 lines
1004 B
Go
package digest
|
|
|
|
import "hash"
|
|
|
|
// Digester calculates the digest of written data. Writes should go directly
|
|
// to the return value of Hash, while calling Digest will return the current
|
|
// value of the digest.
|
|
type Digester interface {
|
|
Hash() hash.Hash // provides direct access to underlying hash instance.
|
|
Digest() Digest
|
|
}
|
|
|
|
// NewDigester create a new Digester with the given hashing algorithm and
|
|
// instance of that algo's hasher.
|
|
func NewDigester(alg string, h hash.Hash) Digester {
|
|
return &digester{
|
|
alg: alg,
|
|
hash: h,
|
|
}
|
|
}
|
|
|
|
// NewCanonicalDigester is a convenience function to create a new Digester with
|
|
// our default settings.
|
|
func NewCanonicalDigester() Digester {
|
|
return NewDigester(CanonicalAlgorithm, CanonicalHash.New())
|
|
}
|
|
|
|
// digester provides a simple digester definition that embeds a hasher.
|
|
type digester struct {
|
|
alg string
|
|
hash hash.Hash
|
|
}
|
|
|
|
func (d *digester) Hash() hash.Hash {
|
|
return d.hash
|
|
}
|
|
|
|
func (d *digester) Digest() Digest {
|
|
return NewDigest(d.alg, d.Hash())
|
|
}
|